using UnityEngine;
using DG.Tweening;
using Ashwild.Player;

namespace Ashwild.Inventory
{
    public class HotbarUI : MonoBehaviour
    {
        [Header("References")]
        [SerializeField] private SlotUI[] hotbarSlot;
        [SerializeField] private CanvasGroup canvasGroup;

        [Header("Animation")]
        [SerializeField] private float idleScale = 0.7f;
        [SerializeField] private float activeScale = 1f;
        [SerializeField] private float idleAlpha = 0.5f;
        [SerializeField] private float activeAlpha = 1f;
        [SerializeField] private float zoomInDuration = 0.15f;
        [SerializeField] private float zoomOutDuration = 0.4f;
        [SerializeField] private float activeHoldDuration = 1.5f;
        [SerializeField] private Ease zoomInEase = Ease.OutBack;
        [SerializeField] private Ease zoomOutEase = Ease.InQuad;

        [Header("Context Menu")]
        [SerializeField] private SlotContextMenu contextMenu;

        [Header("Hover Description")]
        [Tooltip("Same panel used by the inventory — assign the shared HoverDescriptionUI here too.")]
        [SerializeField] private HoverDescriptionUI hoverDescription;

        private PlayerInventory inventory;
        private Tweener scaleTween;
        private Tweener alphaTween;
        private float zoomOutTimer;
        private bool inventoryLocked;
        private bool bound;

        /// <summary>
        /// Waits for the networked local player to spawn before binding to its inventory.
        /// </summary>
        private void OnEnable()
        {
            PlayerEvents.LocalPlayerSpawned += HandleLocalPlayerSpawned;
        }

        /// <summary>
        /// Unsubscribes — mirrors OnEnable exactly.
        /// </summary>
        private void OnDisable()
        {
            PlayerEvents.LocalPlayerSpawned -= HandleLocalPlayerSpawned;
        }

        private void Start()
        {
            // Visual setup that does not need the player.
            for (int i = 0; i < hotbarSlot.Length; i++)
                hotbarSlot[i].Initialize(SlotContainer.Inventory, i,
                    InventoryUI.HandleSlotDrop, OnSlotClicked, OnSlotHoverEnter, OnSlotHoverExit);

            transform.localScale = Vector3.one * idleScale;
            if (canvasGroup != null)
                canvasGroup.alpha = idleAlpha;

            // The player may already exist (late UI init); otherwise we wait for the spawn event.
            if (PlayerInventory.Instance != null)
                BindToInventory();
        }

        /// <summary>
        /// Binds to the inventory as soon as the local player has spawned on the network.
        /// </summary>
        private void HandleLocalPlayerSpawned() => BindToInventory();

        /// <summary>
        /// Hooks the hotbar UI onto the local player's inventory; safe to call more than once.
        /// </summary>
        private void BindToInventory()
        {
            if (bound) return;
            inventory = PlayerInventory.Instance;
            if (inventory == null) return;
            bound = true;

            inventory.onSlotChanged.AddListener(OnSlotChanged);
            inventory.onSelectedSlotChanged.AddListener(OnSelectedSlotChanged);

            RefreshAll();
            UpdateSelection(inventory.SelectedHotbarIndex);
        }

        private void OnDestroy()
        {
            scaleTween?.Kill();
            alphaTween?.Kill();

            if (inventory != null)
            {
                inventory.onSlotChanged.RemoveListener(OnSlotChanged);
                inventory.onSelectedSlotChanged.RemoveListener(OnSelectedSlotChanged);
            }
        }

        private void Update()
        {
            if (inventoryLocked || zoomOutTimer <= 0f) return;

            zoomOutTimer -= Time.deltaTime;
            if (zoomOutTimer <= 0f)
                ZoomOut();
        }

        private void OnSelectedSlotChanged(int selectedIndex)
        {
            UpdateSelection(selectedIndex);
            ZoomIn();
        }

        private void ZoomIn()
        {
            zoomOutTimer = activeHoldDuration;

            scaleTween?.Kill();
            scaleTween = transform.DOScale(activeScale, zoomInDuration).SetEase(zoomInEase);

            if (canvasGroup != null)
            {
                alphaTween?.Kill();
                alphaTween = canvasGroup.DOFade(activeAlpha, zoomInDuration);
            }
        }

        private void ZoomOut()
        {
            scaleTween?.Kill();
            scaleTween = transform.DOScale(idleScale, zoomOutDuration).SetEase(zoomOutEase);

            if (canvasGroup != null)
            {
                alphaTween?.Kill();
                alphaTween = canvasGroup.DOFade(idleAlpha, zoomOutDuration);
            }
        }

        public void OnInventoryOpen()
        {
            inventoryLocked = true;
            zoomOutTimer = 0f;
            ZoomIn();
        }

        public void OnInventoryClose()
        {
            inventoryLocked = false;
            ZoomOut();
        }

        /// <summary>
        /// Right-click on a hotbar slot: a quick deposit into the open chest, otherwise the slot context
        /// menu (only while the inventory window is open — the hotbar must not pop a menu during play).
        /// </summary>
        private void OnSlotClicked(SlotContainer container, int index, bool rightClick)
        {
            if (!rightClick) return;

            if (PlayerEvents.IsChestOpen)
            {
                if (InventoryUI.Instance != null)
                    InventoryUI.Instance.RequestQuickTransfer(SlotContainer.Inventory, index);
                return;
            }

            if (!PlayerEvents.IsInventoryOpen) return;

            if (contextMenu != null)
                contextMenu.Show(index);
            else
                inventory.UseItem(index);
        }

        private void OnSlotChanged(int index)
        {
            if (index >= 0 && index < hotbarSlot.Length)
                hotbarSlot[index].UpdateVisual(inventory.GetSlot(index));
        }

        /// <summary>
        /// Shows the shared description panel for a hovered hotbar slot, but only while the inventory
        /// is open and no chest is open (chest mode hides the description entirely) — during normal play
        /// the hotbar must not pop a description. The duration bar reflects the item's remaining uses.
        /// </summary>
        private void OnSlotHoverEnter(SlotContainer container, int index)
        {
            if (PlayerEvents.IsChestOpen) return;
            if (hoverDescription == null || inventory == null || !PlayerEvents.IsInventoryOpen) return;

            InventorySlot slot = inventory.GetSlot(index);
            if (slot == null || slot.IsEmpty)
            {
                hoverDescription.Hide();
                return;
            }

            hoverDescription.Show(ItemDescriptionView.From(slot));
        }

        /// <summary>
        /// Hides the description panel when the pointer leaves a hotbar slot.
        /// </summary>
        private void OnSlotHoverExit()
        {
            if (hoverDescription != null)
                hoverDescription.Hide();
        }

        private void UpdateSelection(int selectedIndex)
        {
            for (int i = 0; i < hotbarSlot.Length; i++)
                hotbarSlot[i].SetSelected(i == selectedIndex);
        }

        private void RefreshAll()
        {
            for (int i = 0; i < hotbarSlot.Length; i++)
                hotbarSlot[i].UpdateVisual(inventory.GetSlot(i));
        }
    }
}